International mission to measure saltiness of sea

June 6, 2011
By ALICIA CHANG , AP Science Writer

This image provided by NASA shows an artist's conception of the Aquarius/SAC-D spacecraft, a collaboration between NASA and Argentina's space agency, with participation from Brazil, Canada, France and Italy. Aquarius, the NASA-built primary instrument on the spacecraft, will take NASA's first space-based measurements of ocean surface salinity, a key missing variable in satellite observations of Earth that links ocean circulation, the global balance of freshwater and climate. (AP Photo/NASA)

(AP) -- An international mission will chart the saltiness of the ocean - from outer space.

An Argentine-built spacecraft carrying instruments from the United States and other nations is set to launch Thursday from the Vandenberg Air Force Base along the central California coast aboard a Delta 2 rocket.

The craft will circle 408 miles above the Earth and will use a NASA-built instrument to map weekly changes in the levels of brine in the sea. NASA's Aquarius instrument is so sensitive that it can detect changes down to a dash of salt in a gallon of water.

Nearly three-quarters of Earth's surface is covered by water, which contains about 3.5 percent salt. Though the amount of salt in the world's oceans remains mostly unchanged, the brine concentration in the topmost layer varies around the globe.

Understanding how brackish the sea surface is will help researchers better predict future climate change and short-term climate phenomena such as El Nino and its alter ego La Nina, which can have profound effects on weather around the world.

A fleet of Earth-orbiting satellites routinely provides updates on sea surface temperatures, sea level changes and ocean winds. But measurements of dissolved salts in the ocean so far have been limited, sporadically measured by ships and buoys.

"There are vast tracts of the ocean where salinity has never been collected - ever," NASA's Eric Lindstrom said at a pre-launch news conference.

The $287 million Aquarius - Latin for water-bearer and named after the constellation - is designed to measure microwave energy emitted by the ocean, giving scientists an idea of the saltiness. To prevent interference from radio, radar and other noise, another instrument will doublecheck the data and correct for any wrong readings.

The project is a joint venture between NASA and Argentina's space agency CONAE. Other participating countries include Brazil, Canada, France and Italy, which will collect environmental data.

It's not the first to do ocean remote sensing of salt levels. Once in orbit, the spacecraft will join a dual-purpose European satellite that has been collecting data on ocean salt and soil moisture since 2009. Unlike the European mission, the new project is dedicated to the ocean and uses different technology to make measurements. It's not unusual to have several overlapping Earth-observing satellites.

Scientists from both missions plan to combine data and compare results, said Gary Lagerloef of the Seattle-based nonprofit Earth & Space Research.

Related Stories

(PhysOrg.com) -- An international spacecraft that will take NASA's first space-based measurements of ocean surface salinity has arrived at its launch site at Vandenberg Air Force Base in California. The Aquarius/SAC-D mission ...

While most Americans are traveling to family gatherings this week for Thanksgiving, a team of scientists from NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the Goddard Space Flight Center in Greenbelt, Md., are ...

(PhysOrg.com) -- With more than a few stamps on its passport, NASA's Aquarius instrument on the Argentinian Satélite de Aplicaciones Científicas (SAC)-D spacecraft will soon embark on its space mission to "taste" ...

When NASA's salt-seeking Aquarius instrument ascends to the heavens this June, the moon above its launch site at California's Vandenberg Air Force Base won't be in the seventh house, and Jupiter's latest alignment with Mars ...

Recommended for you

Five million years ago, the Colorado River met the Gulf of California near the present-day desert town of Blythe, California. The evidence, say University of Oregon geologists, is in the sedimentary rocks exposed at the edges ...

Pressure, temperature and fluid composition play an important role in the amount of metals and other chemicals found in wastewaters from hydraulically fractured gas reservoirs, according to Penn State researchers.

Pioneering work being carried out in a cave in New Mexico by researchers at McMaster University and The University of Akron, Ohio, is changing the understanding of how antibiotic resistance may have emerged and how doctors ...

(Phys.org)—A team of researchers with the European Commission's Joint Research Centre and Google Switzerland has combined historical data with modern mapping engines to produce high-resolution maps of the world's surface ...

The ice sheet covering Greenland is four times bigger than California—and holds enough water to raise global sea-level more than twenty feet if most of it were to melt. Today, sea levels are rising and the melting of Greenland ...

0 comments

Please sign in to add a comment.
Registration is free, and takes less than a minute.
Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.